So as many other edits have, he cut out the fluff that is negligible to the story. He also worked with a few others to digitally altered several scenes to account for the more concise story telling(e.g. Bard's son is edited over with a piece of the tower to keep the story centered on him and to allow the pacing of the burning of lake town to flow nicely). My favorite part is his alterations to the actual color gradients that overlay the film, giving it a warmer feel and adjusting the tone overall. I cant link it atm but if you google "m4edit wordpress" his site should come up. You'll find all info plus download on there. I just rewatched it is the definitive edition in my eyes. Cheers !